[cobrashoch]

I agree almost in whole with Bill Wells on this one. Go for relative numbers when tunning. To that I would add you can measure drivetrain losses on a rear wheel dyno by switching out drivetrain components too. BTW - it's been my experience that drivetrain losses are a fixed number, regardles of the power that your engine makes. It's usially +/- around 35 horsepower with 4/5 speed sticks and 8.8 Ford rears. A huge horsepower varible I've found, esp. on Cobras, is the exhaust system. Big time losses and gains are made here on Cobras, so pay attention to this. Good luck on your new toy!
cobrashock